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Selected AbstractsCognitive training in Alzheimer's disease: a meta-analysis of the literatureACTA PSYCHIATRICA SCANDINAVICA, Issue 2 2006D. I. Sitzer Objective:, To systematically review the literature and summarize the effect of cognitive training (CT) for Alzheimer's disease (AD) patients on multiple functional domains. Method:, Effect sizes (Cohen's d) were calculated for 17 controlled studies identified through a comprehensive literature review. Results:, An overall effect size of 0.47 was observed for all CT strategies across all measured outcomes. Mean effect sizes were higher for restorative (0.54) than for compensatory (0.36) strategies. Domain-specific effect sizes ranged from 2.16 (verbal and visual learning) to ,0.38 (visuospatial functioning). Data are also presented on the relative impact of restorative and compensatory strategies for each domain of functioning. Conclusion:, CT evidenced promise in the treatment of AD, with primarily medium effect sizes for learning, memory, executive functioning, activities of daily living, general cognitive problems, depression, and self-rated general functioning. Restorative strategies demonstrated the greatest overall effect on functioning. Several limitations of the published literature are discussed. [source] A New Look at Husbands' and Wives' Time AllocationJOURNAL OF CONSUMER AFFAIRS, Issue 1 2004MOHAMMAD ALENEZI The impacts of economic and non-economic factors on husbands' and wives' market work time and housework time are estimated using 13 years of data from the Panel Survey of Income Dynamics. Several limitations in earlier studies are addressed, and a unique feature of the study is the direct estimation of effects on time allocation from changes in the prices of market-produced goods and input goods in household production. Many of the findings of earlier studies are reconfirmed, but new insights are also explored. Husbands and wives respond similarly in their time allocations to changes in input goods prices, but their responses are different to changes in market goods prices. [source] Sexually antagonistic coevolution in insects is associated with only limited morphological diversityJOURNAL OF EVOLUTIONARY BIOLOGY, Issue 3 2006W. Eberhard Abstract Morphological traits involved in male,female sexual interactions, such as male genitalia, often show rapid divergent evolution. This widespread evolutionary pattern could result from sustained sexually antagonistic coevolution, or from other types of selection such as female choice or selection for species isolation. I reviewed the extensive but under-utilized taxonomic literature on a selected subset of insects, in which male,female conflict has apparently resulted in antagonistic coevolution in males and females. I checked the sexual morphology of groups comprising 500,1000 species in six orders for three evolutionary trends predicted by the sexually antagonistic coevolution hypothesis: males with species-specific differences and elaborate morphology in structures that grasp or perforate females in sexual contexts; corresponding female structures with apparently coevolved species-specific morphology; and potentially defensive designs of female morphology. The expectation was that the predictions were especially likely to be fulfilled in these groups. A largely qualitative overview revealed several surprising patterns: sexually antagonistic coevolution is associated with frequent, relatively weak species-specific differences in males, but male designs are usually relatively simple and conservative (in contrast to the diverse and elaborate designs common in male structures specialized to contact and hold females in other species, and also in weapons such as horns and pincers used in intra-specific battles); coevolutionary divergence of females is not common; and defensive female divergence is very uncommon. No cases were found of female defensive devices that can be facultatively deployed. Coevolutionary morphological races may have occurred between males and females of some bugs with traumatic insemination, but apparently as a result of female attempts to control fertilization, rather than to reduce the physical damage and infections resulting from insertion of the male's hypodermic genitalia. In sum, the sexually antagonistic coevolution that probably occurs in these groups has generally not resulted in rapid, sustained evolutionary divergence in male and female external sexual morphology. Several limitations of this study, and directions for further analyses are discussed. [source] Conceptualizing Emerging Adulthood: Inspecting the Emperor's New Clothes?CHILD DEVELOPMENT PERSPECTIVES, Issue 2 2007Leo B. Hendry ABSTRACT,Jeffrey Arnett's concept of emerging adulthood is critically examined by reviewing and evaluating elements of its theoretical framework and by referring to relevant empirical studies, which support the major arguments presented. Several limitations to Arnett's model are found and an alternative perspective is offered that might complement his stage theory and provide a stronger theoretical baseline for future research. [source] Update on therapeutic options in Waldenström macroglobulinemiaEUROPEAN JOURNAL OF HAEMATOLOGY, Issue 1 2009Xavier Leleu Abstract Waldenström macroglobulinemia (WM) is a B-cell disorder characterized primarily by bone marrow infiltration with lymphoplasmacytic cells (LPCs), along with demonstration of an IgM monoclonal gammopathy in the blood. WM remains incurable, with 5,6 yr median overall survival for patients with symptomatic WM. The main therapeutic options include alkylating agents, nucleoside analogues, and rituximab, either in monotherapy or in combination. Studies involving combination chemotherapy are ongoing, and preliminary results are encouraging. However, there are several limitations to these approaches. The complete response rate is low and the treatment free survival are short in many patients, no specific agent or regimen has been shown to be superior to another, and no treatment has been specifically approved for WM. As such, novel therapeutic agents are needed for the treatment of WM. In ongoing efforts, we and others have sought to exploit advances made in the understanding of the biology of WM so as to develop new targeted therapeutics for this malignancy. These efforts have led to the development of proteasome inhibitors, of them bortezomib, several Akt/mTor inhibitors, such as perifosine and Rad001, and immunomodulatory agents such as thalidomide and lenalidomide. Many agents and monoclonal antibodies are currently being tested in clinical trials and seem promising. This report provides an update of the current preclinical studies and clinical efforts for the development of novel agents in the treatment of WM. [source] The ecology and agronomy of Miscanthus sinensis, a species important to bioenergy crop development, in its native range in Japan: a reviewGCB BIOENERGY, Issue 2 2009J. RYAN STEWART Abstract Among several candidate perennial taxa, Miscanthus×giganteus has been evaluated and promoted as a promising bioenergy crop. Owing to several limitations, however, of the sterile hybrid, both at the taxon and agronomic production levels, other options need to be explored to not only improve M. ×giganteus, which was originally collected in Japan, but to also consider the development of other members of its genus, including Miscanthus sinensis, as bioenergy crops. Indeed, there is likely much to be learned and applied to Miscanthus as a bioenergy crop from the long history of intensive interaction between humans and M. sinensis in Japan, which in some regions of the country spans several thousand years. Combined with its high amount of genetic variation, stress tolerance, biotic interactions with fauna, and function as a keystone species in diverse grasslands and other ecosystems within its native range, the unique and extensive management of M. sinensis in Japan as a forage grass and building material provides agronomists, agroecologists, and plant breeders with the capability of better understanding this species in terms of potential contribution to bioenergy crop development. Moreover, the studies described in this review may serve as a platform for future research of Miscanthus as a bioenergy crop in other parts of the world. [source] Size and book to market effects and the Fama French three factor asset pricing model: evidence from the Australian stockmarketACCOUNTING & FINANCE, Issue 1 2004Clive Gaunt Abstract The present study adds to the sparse published Australian literature on the size effect, the book to market (BM) effect and the ability of the Fama French three factor model to account for these effects and to improve on the asset pricing ability of the Capital Asset Pricing Model (CAPM). The present study extends the 1981,1991 period examined by Halliwell, Heaney and Sawicki (1999) a further 10 years to 2000 and addresses several limitations and findings of that research. In contrast to Halliwell, Heaney and Sawicki the current study finds the three factor model provides significantly improved explanatory power over the CAPM, and evidence that the BM factor plays a role in asset pricing. [source] The British partnership phenomenon: a ten year reviewHUMAN RESOURCE MANAGEMENT JOURNAL, Issue 3 2009Stewart Johnstone This article presents a detailed review of the vast partnership literature that has emerged in the UK between 1998 and 2008. It begins by examining definitions of partnership, and suggests that while academic definitions are vague, practitioner definitions tend to conflate partnership processes with partnership outcomes. An alternative definition based upon processes and practices is offered. This is followed by a review of the conceptual advocates/critics debate, and the key themes of empirical partnership studies. It is proposed that while recent empirical evidence identifies a variety of outcomes and presents various typologies of partnership, there is an absence of debates on typologies in the literature. The article then identifies several limitations of the existing literature, including ideological positions, a lack of sensitivity to context and to different types of partnership, and a focus on outcomes. The article concludes by suggesting avenues for future partnership research. [source] An improved AMC-coupled runoff curve number modelHYDROLOGICAL PROCESSES, Issue 20 2010Ram Kumar Sahu Abstract In the Soil Conservation Service Curve Number (SCS-CN) method, the three levels of antecedent moisture condition (AMC) permit unreasonable sudden jumps in curve numbers, which result into corresponding jumps in the estimated runoff. A few recently developed SCS-CN-based models obviate this problem, yet they have several limitations. In this study, such a model incorporating a continuous function for antecedent moisture has been presented. It has several advantages over the other existing SCS-CN-based models. Its application to a large dataset from US watersheds showed to perform better than the existing SCS-CN method and the others based on it. Copyright © 2010 John Wiley & Sons, Ltd. [source] Validity of the indicator ,death in low-mortality diagnosis-related groups' for measuring patient safety and healthcare quality in hospitalsINTERNAL MEDICINE JOURNAL, Issue 4 2010S. Mihrshahi Abstract The indicator ,death in low-mortality diagnosis-related groups (DRG)' is a patient safety indicator (PSI) that can be derived from routinely collected administrative data sources. It is included in a group of PSI that have been proposed to compare and monitor standards of hospital care in Australia. To summarize the attributes of this indicator as a measure of quality and safety in healthcare and examine issues regarding the development process, definitions and use of the indicator in practice. A structured literature search was conducted using the Ovid Medline database to identify peer-reviewed published literature which used ,death in low-mortality DRG' as a quality/safety indicator. Key quality websites were also searched. The studies were critically appraised using a standardized method. A total of 12 articles was identified which met our search criteria. Most were of low methodological quality because of their retrospective study designs. Only three studies provided evidence that the quality of care gap is higher in ,deaths in low-mortality DRG' than in other cases. Most of the studies reviewed show that there are several limitations of the indicator for assessing patient safety and quality of care. The few studies that have assessed associations with other measures of hospital quality have shown only weak and inconsistent associations. Higher quality, prospective, analytic studies are required before ,death in low-mortality DRG' is used as an indicator of quality and safety in healthcare. Based on current evidence, the most appropriate use is as a screening tool for institutions to quickly and easily identify a manageable number of medical records to investigate in more detail. [source] Long-term control of mycosis fungoides of the hands with topical bexaroteneINTERNATIONAL JOURNAL OF DERMATOLOGY, Issue 3 2003Ted Lain BA Background Limited Stage IA mycosis fungoides (MF) is often treated with topical steroids, which can cause atrophy, or with nitrogen mustard, which imposes several limitations on the patient's lifestyle. Topical bexarotene is a novel synthetic rexinoid with few side-effects that has shown efficacy for treatment of mycosis fungoides skin lesions in recent Phase II,III clinical trials. The Phase I,II trial involving 67 stage IA,IIA MF patients demonstrated complete response (CR) in 21% and partial response (PR) in 42% of the patients. The median time to response was approximately 20 weeks. In the phase III trial of refractory stage IA, IB and IIA MF, the patients demonstrated a 44% response rate (8% CR). Patients with no prior therapy for mycosis fungoides responded at a higher rate (75%) than those with prior topical therapies. Methods Case report of a patient with MF limited to the hands treated with topical bexarotene 0.1% gel in a open label phase II clinical trial. Results Partial response occurred after 2 weeks of topical bexarotene therapy and the lesions were well controlled for 5 years using bexarotene monotherapy, with only occasional mild local irritation. Conclusions Topical bexarotene is effective as long-term treatment monotherapy for limited MF lesions. To our knowledge this is the longest use of the drug by any individual. [source] A stratified first order logic approach for access controlINTERNATIONAL JOURNAL OF INTELLIGENT SYSTEMS, Issue 9 2004Salem Benferhat Modeling information security policies is an important problem in many domains. This is particularly true in the health care sector, where information systems often manage sensitive and critical data. This article proposes to use nonmonotonic reasoning systems to control access to sensitive data in accordance with a security policy. In the first part of the article, we propose an access control model that overcomes several limitations of existing systems. In particular, it allows us to deal with contexts and to represent the two main kinds of privileges: permissions and prohibitions. This model will then be formally encoded using stratified (or prioritized) first-order knowledge bases. In the second part of the article, we discuss the problem of conflicts due to the joint handling of permissions and prohibitions. We show that approaches proposed for solving conflicts in propositional knowledge bases are not appropriate for handling inconsistent first-order knowledge bases. © 2004 Wiley Periodicals, Inc. Int J Int Syst 19: 817,836, 2004. [source] Two Dimensions of Attachment to God and Their Relation to Affect, Religiosity, and Personality ConstructsJOURNAL FOR THE SCIENTIFIC STUDY OF RELIGION, Issue 4 2002Wade Rowatt In this study we sought to address several limitations of previous research on attachment theory and religion by (1) developing a dimensional attachment to God scale, and (2) demonstrating that dimensions of attachment to God are predictive of measures of affect and personality after controlling for social desirability and other related dimensions of religiosity. Questionnaire measures of these constructs were completed by a sample of university students and community adults (total n= 374). Consistent with prior research on adult romantic attachment, two dimensions of attachment to God were identified: avoidance and anxiety. After statistically controlling for social desirability, intrinsic religiousness, doctrinal orthodoxy, and loving God image, anxious attachment to God remained a significant predictor of neuroticism, negative affect, and (inversely) positive affect; avoidant attachment to God remained a significant inverse predictor of religious symbolic immortality and agreeableness. These findings are evidence that correlations between attachment to God and measures of personality and affect are not merely byproducts of confounding effects of socially desirable responding or other dimensions of religiosity. [source] Measuring diagnostic and predictive accuracy in disease management: an introduction to receiver operating characteristic (ROC) analysisJOURNAL OF EVALUATION IN CLINICAL PRACTICE, Issue 2 2006Ariel Linden DrPH MS Abstract Diagnostic or predictive accuracy concerns are common in all phases of a disease management (DM) programme, and ultimately play an influential role in the assessment of programme effectiveness. Areas, such as the identification of diseased patients, predictive modelling of future health status and costs and risk stratification, are just a few of the domains in which assessment of accuracy is beneficial, if not critical. The most commonly used analytical model for this purpose is the standard 2 × 2 table method in which sensitivity and specificity are calculated. However, there are several limitations to this approach, including the reliance on a single defined criterion or cut-off for determining a true-positive result, use of non-standardized measurement instruments and sensitivity to outcome prevalence. This paper introduces the receiver operator characteristic (ROC) analysis as a more appropriate and useful technique for assessing diagnostic and predictive accuracy in DM. Its advantages include; testing accuracy across the entire range of scores and thereby not requiring a predetermined cut-off point, easily examined visual and statistical comparisons across tests or scores, and independence from outcome prevalence. Therefore the implementation of ROC as an evaluation tool should be strongly considered in the various phases of a DM programme. [source] International Differences in Nursing Research, 2005,2006JOURNAL OF NURSING SCHOLARSHIP, Issue 1 2009Denise F. Polit PhD Abstract Purpose: To compare the characteristics of nursing research being done in different countries, using data from studies published in nonspecialty, English-language nursing journals. Design: Data for this cross-sectional analysis were retrieved from a consecutive sample of 1,072 studies published in eight leading English-language research journals in 2005 and 2006. Methods: For each study, data were extracted on the characteristics of the study participants and authors, study focus-specialty area, funding, and methodologic attributes. Studies from 15 countries or regional groupings were compared. Findings: International differences in authors, participants, and study characteristics were typically large and statistically significant. Studies that were focused on nurses were especially prevalent in Europe, Australia, and Canada, whereas patient-centered studies were most common in Asian countries and the US. Qualitative studies were predominant in Norway, Sweden, and the UK. Asian nurse researchers, by contrast, undertook mostly quantitative studies, and were especially likely to conduct intervention research. Significant country differences existed in the omission of demographic (age and sex) information about participants, with omissions most prevalent in the UK and Ireland and least prevalent in Asian countries. Research funding was reported for 62% of all studies, ranging from 13% in Turkey to over 75% in Canada and the US. Conclusions: Although this study had several limitations, especially with regard to potential biases in the sample of studies from non-English-speaking countries, this analysis of over 1,000 nursing studies indicates many important inter-country differences in the focus, methods, and authorship patterns of nursing research published in leading journals. Clinical Relevance: Because research "informs" practice, international differences that exist in the focus and methods of nursing research have implications for nursing practice in the respective countries. [source] Fabrication of Artificial Petal Sculptures by Replication of Sub-micron Surface Wrinkles,MACROMOLECULAR CHEMISTRY AND PHYSICS, Issue 2 2010Alexandra Schweikart Abstract In this contribution, we discuss wrinkling as a process resulting in well-defined periodic micron-sized structures, as known from the interface of several plant cells. We show possible pathways to transfer this principle to artificial materials such as epoxy resins or polymers. While topographical structuring of surfaces by wrinkling is meanwhile well established for elastomers like poly (dimethyl siloxane), so far the step towards other classes of materials has not been taken. This puts several limitations to potential applications of artificial wrinkled structures, as elastomers show poor dimensional stability, low optical quality, and tend to swell in organic solvents. As well, artificial structures formed by wrinkling are not tension-free on the microscopic level, which makes them metastable. Residual mechanical tensions can affect dimensional stability on long timescales. We introduce two processes, micro thermoforming and molding, as means to overcome these restrictions and to pattern non-elastomeric materials by using wrinkled elastomers as templates. The two approaches allow the formation of negative and positive replicas and allow the transfer of sub-micron features with high fidelity. [source] Corrosion aspects of metallic implants , An overviewMATERIALS AND CORROSION/WERKSTOFFE UND KORROSION, Issue 11 2008A. Balamurugan Abstract The ability to replace or augment diseased body parts totally or partially has improved both the quality and life span of human population. The decline in surgical risks during recent decades has encouraged the development of more complex procedures for prosthetic implantation. Additionally, a variety of extracorporeal devices, such as the heart, lung and blood dialysis machines are used routinely, but these prosthetic elements have several limitations. Hence, research projects are currently underway to overcome the limitations of synthetic materials by developing formulations with varying properties, such as asymptomatic, long-term function in the human physiological environment, etc., to meet the needs of biomedical surgeons. This review focuses on the several biomaterials corrosion and its measures to prevent corrosion. [source] Nondestructive optical determination of fiber organization in intact myocardial wallMICROSCOPY RESEARCH AND TECHNIQUE, Issue 7 2008Rebecca M. Smith Abstract Mapping the myocardial fiber organization is important for assessing the electrical and mechanical properties of normal and diseased hearts. Current methods to determine the fiber organization have several limitations: histological sectioning mechanically distorts the tissue and is labor-intensive, while diffusion tensor imaging has low spatial resolution and requires expensive MRI scanners. Here, we utilized optical clearing, a fluorescent dye, and confocal microscopy to create three-dimensional reconstructions of the myocardial fiber organization of guinea pig and mouse hearts. We have optimized the staining and clearing procedure to allow for the nondestructive imaging of whole hearts with a thickness up to 3.5 mm. Myocardial fibers could clearly be identified at all depths in all preparations. We determined the change of fiber orientation across strips of guinea pig left ventricular wall. Our study confirms the qualitative result that there is a steady counterclockwise fiber rotation across the ventricular wall. Quantitatively, we found a total fiber rotation of 105.7 ± 14.9° (mean ± standard error of the mean); this value lies within the range reported by previous studies. These results show that optical clearing, in combination with a fluorescent dye and confocal microscopy, is a practical and accurate method for determining myocardial fiber organization. Microsc. Res. Tech., 2008. © 2008 Wiley-Liss, Inc. [source] Glutamic acid decarboxylase and IA-2 autoantibodies in type 1 diabetes: comparing sample substrates for autoantibody determinationsPEDIATRIC DIABETES, Issue 1 2000C Wasserfall Large-scale programs designed to assess risk for type 1 diabetes through serologic assessment of autoantibodies to recombinant ,-cell autoantigens are hampered by several limitations, including the methods for sample collection and assay performance, as well as the volume required for autoantibody determinations. The present study was designed to develop a low sample-volume, primary screening method for autoantibody detection of high specificity and sensitivity, and to determine the feasibility of dried blood spots collected on filter paper in serving as vehicles for such determinations. Autoantibodies to glutamic acid decarboxylase (GAD) and ICA512bdc (IA-2), both individually and in combination, were determined in persons with type 1 diabetes, healthy controls, or individuals with other autoimmune disorders. Autoantibody results for serum, plasma, and dried blood spots were compared. GAD, IA-2, and combined GAD/IA-2 autoantibodies were concordant in their measurement from minimal volumes of serum, plasma, and whole blood extracted from dried filter paper. The autoantibody levels from the dried blood spots were, however, lower than corresponding serum samples, and, as currently designed, failed to detect low-titer autoantibodies. Despite this limitation, screening for diabetes risk can be performed using small volumes of whole blood, serum, or plasma collected onto filter paper. These methodological improvements should simplify matters, reduce costs, and increase the efficacy of screening programs for type 1 diabetes. Further development of better substrates/methods for blood-specimen collection seems necessary to exploit the full potential of this and other autoantibody measurement strategies for screening large populations. [source] Antihypertensive drug therapy and the risk of lower extremity amputations in pharmacologically treated type 2 diabetes patients,PHARMACOEPIDEMIOLOGY AND DRUG SAFETY, Issue 3 2004Joëlle A. Erkens PharmD Abstract Purpose The objective of this study was to determine the association between different antihypertensive drug therapies and lower extremity amputations (LEAs) in type 2 diabetes patients. Methods Data were obtained from the PHARMO Record Linkage System comprising pharmacy records and data on hospitalisations for all 450,000 residents of eight Dutch cities. In a nested case-control study among 12,140 type 2 diabetes patients who used antihypertensive drugs, 26 cases with a first LEA and 94 controls without a LEA matched on age, sex and calendar time were identified. Logistic regression was used to estimate the relative risk of LEA and to adjust for potential confounding factors. Results Among type 2 diabetes patients who used antihypertensive drugs, subjects who used thiazide diuretics, alone or in combination, had a higher risk of LEA compared to subjects who used Angiotensin Converting Enzyme (ACE) inhibitor monotherapy (crude odds ratio (OR): 6.11 [95% confidence interval (CI): 1.32,28.27]). The use of thiazide diuretics was also associated with an increased risk of LEA when compared to the use of any non-thiazide antihypertensive drug (adjusted OR: 7.04 [1.10,45.30]). The increased risk of LEA associated with the use of thiazides compared to the use of non-thiazides depended on the duration of use (adjusted OR,365 days, 4.82 [0.61,38.34] and adjusted OR>365 days, 26.16 [1.02,674.02], p -trend,=,0.01). Conclusions Treatment with thiazide diuretics compared to treatment with other antihypertensive drugs was associated with excess amputations in type 2 diabetes patients. Due to several limitations of this study, our findings do not preclude the use of thiazides in type 2 diabetes mellitus patients as yet. Copyright © 2004 John Wiley & Sons, Ltd. [source] Revising the Personality Disorder Diagnostic Criteria for the Diagnostic and Statistical Manual of Mental Disorders-Fifth Edition (DSM-V): Consider the Later Life ContextAMERICAN JOURNAL OF ORTHOPSYCHIATRY, Issue 4 2009Steve Balsis PhD The categorical measurement approach implemented by the Diagnostic and Statistical Manual of Mental Disorders-Fourth Edition (DSM-IV) personality disorder (PD) diagnostic system is theoretically and pragmatically limited. As a result, many prominent psychologists now advocate for a shift away from this approach in favor of more conceptually sound dimensional measurement. This shift is expected to improve the psychometric properties of the personality disorder (PD) diagnostic system and make it more useful for clinicians and researchers. The current article suggests that despite the probable benefits of such a change, several limitations will remain if the new diagnostic system does not closely consider the context of later life. A failure to address the unique challenges associated with the assessment of personality in older adults likely will result in the continued limited validity, reliability, and utility of the Diagnostic and Statistical Manual of Mental Disorders (DSM) system for this growing population. This article discusses these limitations and their possible implications. [source] Educational and Research Implications of Portable Human Patient Simulation in Acute Care MedicineACADEMIC EMERGENCY MEDICINE, Issue 11 2008Leo Kobayashi MD Abstract Advanced medical simulation has become widespread. One development, the adaptation of simulation techniques and manikin technologies for portable operation, is starting to impact the training of personnel in acute care fields such as emergency medicine (EM) and trauma surgery. Unencumbered by cables and wires, portable simulation programs mitigate several limitations of traditional (nonportable) simulation and introduce new approaches to acute care education and research. Portable simulation is already conducted across multiple specialties and disciplines. In situ medical simulations are those carried out within actual clinical environments, while off-site portable simulations take place outside of clinical practice settings. Mobile simulation systems feature functionality while moving between locations; progressive simulations are longer-duration events using mobile simulations that follow a simulated patient through sequential care environments. All of these variants have direct applications for acute care medicine. Unique training and investigative opportunities are created by portable simulation through four characteristics: 1) enhancement of experiential learning by reframing training inside clinical care environments, 2) improving simulation accessibility through delivery of training to learner locations, 3) capitalizing on existing care environments to maximize simulation realism, and 4) provision of improved training capabilities for providers in specialized fields. Research agendas in acute care medicine are expanded via portable simulation's introduction of novel topics, new perspectives, and innovative methodologies. Presenting opportunities and challenges, portable simulation represents an evolutionary progression in medical simulation. The use of portable manikins and associated techniques may increasingly complement established instructional measures and research programs at acute care institutions and simulation centers. [source] Right ventricular myocardial isovolumic relaxation time and pulmonary pressureCLINICAL PHYSIOLOGY AND FUNCTIONAL IMAGING, Issue 1 2006Pulsed Doppler tissue imaging in resurrection of Burstin's nomogram Summary Aims:, Non-invasive assessment of pulmonary artery systolic pressure (PASP) has several limitations. As previously described by Burstin, the right ventricular (RV) isovolumic relaxation time (IVRt) is sensitive to changes in PASP. We therefore compared RV myocardial IVRt, derived by Doppler tissue imaging (DTI), with simultaneously measured invasive PASP. Methods and results:, Twenty-six consecutive patients (18 males, mean age 52 ± 12 years, range 23,75) underwent a simultaneous Doppler echocardiography, including DTI, and cardiac catheterization examination for measurement of PASP and right atrial mean pressures. IVRt was measured using the myocardial velocities by pulsed DTI at both basal and mid cavity segments of the RV free wall. As diastolic time intervals are influenced by heart rate IVRt was corrected for heart rate (IVRt/RR%). A significant correlation was found between PASP and regional IVRt/RR% at both the basal (r = 0·42, P<0·05) and mid cavity segment (r = 0·71, P<0·001). Furthermore, when only patients with normal right atrial pressures (<7 mmHg) were taken into account, the correlation coefficient improved at both basal and mid cavity segments (r = 0·74, P<0·05 and r = 0·83, P<0·01). Conclusion:, Pulsed Doppler-derived IVRt correlates well with PASP. The use of pulsed DTI for measurement of IVRt is simple, reproducible and easy to obtain. We propose this method as an additional non-invasive tool in the assessment of PASP. [source] | ||||||||||||||||||||||